Rapid policy shifts, sustainability targets, and process-level innovations have fundamentally reshaped the global biofuel landscape over the past three years, writes Dr Raj Shah, Diogo Moscato and Mathew Stephen Roshan.
This review examines recent technological, regulatory, and market-driven developments in corn- and sugarcane-based ethanol production, with emphasis on advances realised between 2023 and 2025.
In corn ethanol systems, enzyme-enabled process enhancements have improved starch and fibre conversion efficiency, increasing ethanol yields without additional land use while simultaneously strengthening coproduct markets such as distillers dried grains with solubles (DDGS) and biochar. Parallel progress in carbon capture and storage has enabled ethanol producers to enter voluntary carbon markets, reducing lifecycle carbon intensity and improving economic resilience.
In sugarcane ethanol, the integration of second-generation (2G) pathways using agricultural residues has expanded operational windows and improved overall resource efficiency, while advances in genetic improvement techniques have accelerated yield gains and climate adaptability.
These technological developments have been reinforced by evolving blending mandates and renewable fuel policies in major markets, including Brazil, the European Union, and emerging aviation and marine fuel sectors.
Collectively, these changes explain the surge in investment and capacity expansion observed globally and signal a transition of ethanol from a compliance fuel towards a strategically optimised, low-carbon energy carrier. Understanding these converging drivers is essential for guiding future research, industrial deployment, and policy design in biofuel systems.
Introduction
The transport industry produces significant greenhouse gas (GHG) emissions, such as CO₂ and methane.
These gases absorb and re-emit infrared radiation, trapping heat in the atmosphere and contributing to global warming and climate change. As a result, renewable and environmentally sustainable fuels are increasingly important.
Ethanol, derived from corn and sugarcane, is already widely used and, in some cases, mandated in the global fuel industry.
Corn and sugarcane are used to produce ethanol because they are rich in fermentable carbohydrates and have well-established production methods.
A factor limiting sugarcane’s global spread is the climate required for cultivation.
Recent advances in biofuel technology include improved enzymes, higher-yield crops and processes that use crop residues to boost yields.
These developments, alongside renewable energy and carbon-reduction efforts, are strengthening collaboration in the sector.
Despite these developments, there remains a need to examine and consolidate the latest progress in biofuel technologies, particularly over the past three years.
Therefore, this review highlights the major technological and sustainability-driven innovations in ethanol during this period. Understanding these advances is essential for future research, global sustainability, and industrial optimisation in the sector.
Advances in corn-based ethanol
2.1. Enzyme and process enhancement
Over the past three years, significant effort has been directed towards developing techniques to improve yield without expanding land use.
Enzyme technology is a key solution: specific enzymes are now applied directly to the crop or during processing, boosting DDGS (distillers’ dried grains) and ethanol production by facilitating more efficient breakdown of plant material, as shown in Table 1.
This technology is estimated to increase overall ethanol production by 10% [2]. Crucially, these enzymes require only a financial investment, as no additional machinery or space is needed to realise these gains.
